Laparoscopic retrieval of disconnected ventriculoperitoneal shunt catheters: report of two cases

Two patients previously treated with ventriculoperitoneal shunt for hydrocephalus had the distal catheters disconnected, and they migrated to the free peritoneal cavity. The signs and symptoms of increased intracranial pressure occurred as a result of mechanical failure of the shunt system. Both patients successfully underwent a laparoscopic retrieval of the catheters using endoscopic grasping forceps, and revision of the ventriculoperitoneal shunt by inserting the new catheters into the peritoneal cavity was performed through a small entrance for the laparoscope. Recently, conventional laparotomy has been often replaced by laparoscopic surgery, and general surgeons are well familiar with the laparoscopic procedures. The significant advantage of this procedure is the ability to explore the entire peritoneal cavity for both diagnosis and treatment, and it is by far a less invasive approach than conventional laparotomy. The present report describes the laparoscopic procedure for removal of the migrated catheters and discusses its advantages over conventional laparotomy.

Sperm immobilizing antibodies interfere with sperm migration from the uterine cavity through the fallopian tubes

PROBLEM

It is well known that sperm migration in cervical mucus is impaired by sperm immobilizing antibodies secreted in the mucus. However, it is not clear yet whether sperm migration from the uterine cavity through the fallopian tubes to the peritoneal cavity is impaired by sperm immobilizing antibodies. To test the possible impairment of sperm migration in the tubes, laparoscopic examinations were carried out and the presence of motile sperm in the peritoneal fluid after intra-uterine insemination was investigated.

METHOD

Peritoneal sperm recovery tests were performed in 28 infertile women with sperm immobilizing antibodies in their sera, and the results were compared with those in 322 infertile women without the antibodies. Both the sperm immobilizing antibody titers (SI50) and complement activities (C'H50) in peritoneal fluid were compared with those in patients' sera. In some experiments, the supernatant of the peritoneal fluid was used as a source of complement for the sperm immobilization tests instead of guinea pig serum.

RESULTS

Among couples with normal semen characteristics by the criteria of WHO, sperm recovery in the peritoneal fluid was observed in only 3 (11.1%) of 27 patients with sperm immobilizing antibodies, compared with 72 (34.0%) of 212 patients without the antibodies (P < 0.025). The antibody titers of the patients with the sperm recovery were very low by the quantitative sperm immobilization test. In most patients, a similar amount of sperm immobilizing antibodies was present in the peritoneal fluid and the sera. Though the complement activities in the peritoneal fluid were less than those in sera, the former were still found to be sufficient to immobilize sperm in vivo.

CONCLUSIONS

These results suggest that the complement-dependent sperm immobilizing antibodies could interfere with sperm migration in the female genital tract at the level of the fallopian tubes.

[The effect of indomethacin suppository in preventing mesenteric traction syndrome]

Mesenteric traction syndrome consists of cutaneous hyperemia with hypotension and tachycardia. NSAIDs could inhibit the phenomenon, but there are few reports about when to administer these drugs. In this study, we evaluated the effect of indomethacin on preventing mesenteric traction syndrome when administered preoperatively and just after induction of anesthesia. Thirty-six patients scheduled for abdominal hysterectomy were studied. Patients were randomized into three groups. Group C (n = 12); control, group T (n = 12); indomethacin 50 mg suppository just after induction of anesthesia, group P (n = 12); indomethacin 50 mg suppository about 90 min before incision. The effect of indomethacin was evaluated from the extent of cutaneous hyperemia. MTS was suppressed in group P, but not in group T (P < 0.05). We concluded that indomethacin suppository just after induction could not prevent mesenteric traction syndrome.

[Assessment of bone mineralization of hemodialyzed patients with SPA and DPA--different effect of PTX with the site]

We analyzed the bone changes at each site of secondary hyperparathyroidism (2 degrees HPT) on hemodialyzed patients using both single photon absorptiometry (SPA) and dual photon absorptiometry (DPA). The subjects were 35 hemodialysis patients (12 male, 24 female) with 2 degrees HPT. The bone mineral densities (BMD) of 1/3 radius, head, total body and 3rd lumbar spine were measured before and after parathyroidectomy (PTX). Before PTX, the BMD of 2 degrees HPT patients were lower than the normal range of all sites, especially at the radius which mainly consisted of cortical bone. After PTX, the BMD at all sites increased especially in the head. The BMD of the radius also continued to increased up two years after PTX, but it was not as increased as the BMD of head. The BMD of the lumbar spine which consisted of cancellous bone mainly increased after PTX for one year and decreased thereafter. This decrease was influenced by age. There was a difference with the site of BMD after PTX. The determination of changes of BMD of head and radius was considered useful for the judgment of treatment.

Direct production of the Fab fragment derived from the sperm immobilizing antibody using polymerase chain reaction and cDNA expression vectors

PROBLEM

Sperm immobilizing antibodies cause infertility mainly through complement dependent sperm immobilization. To analyze any effect of sperm immobilizing antibody on fertilization, we had already established cell lines that secrete IgM monoclonal antibody (MAb H6-3C4) and IgG monoclonal antibody (MAb EnBCMGS). The latter was a class-switched recombinant IgG antibody that shares the same variable region as MAb H6-3C4. The biological effects of the IgG antibody were also reported previously to eliminate sperm immobilizing or sperm agglutinating activities. However, the method of chemical digestion of IgG had some disadvantage to prepare the purified Fab fragment stably and in large quantities. This time we report a unique method to obtain the recombinant Fab fragments (Fab EnBCMGS) using polymerase chain reaction (PCR) and cDNA expression vectors.

METHOD

Two kinds of PCR primers were designed to make a truncated heavy chain (Fd) gene of MAb EnBCMGS. The amplified Fd gene and light chain gene were ligated into cDNA expression vectors and then transfected into mammalian cells.

RESULTS

Expression of the Fd gene and light chain gene were confirmed by Northern blotting. Secretion of the recombinant Fab fragment from mammalian cells was also confirmed by Western blotting. The Fab fragment showed biological activity as is expected by FACS analysis.

CONCLUSION

This method enables the stable production of genuine Fab fragments of IgG in mammalian cells without any chemical treatment that may be time consuming and affect the quality of the Fab fragments.

Mammalian 60-kDa stress protein (chaperonin homolog). Identification, biochemical properties, and localization

Mammalian chaperonin homolog (HSP60) was purified from porcine livers cytosol using a tandem ATP-Sepharose column and Mono Q column chromatography. A partial amino acid sequence (96 amino acid residues) of this protein was determined and coincided with those of human HSP60 with 96.9% homology, which was deduced from the nucleotide sequence of the cDNA. The sequence of the NH2 termini of the purified protein (5 amino acid residues) coincided with the signal sequence of HSP60. These facts led to the identification of the 60-kDa liver protein with the chaperonin homolog. Dihydrofolate reductase was able to form a stable complex with the liver chaperonin homolog. The liver chaperonin homolog was detected by at least five spots around pI = 5.6 on two-dimensional gel electrophoresis. Immunoblotting studies using an antibody against chaperonin homolog showed that the chaperonin homolog was localized in the cytosol, mitochondrial, and nuclear fractions of porcine liver. The chaperonin homolog was localized both in the mitochondria and cytoplasm of rat kidneys at the electron microscopic level. The chaperonin homolog in the cytosol, but not in the other subcellular fractions, was cross-reacted with an antibody against the synthetic peptide corresponding to the signal peptide of HSP60 as well as the purified chaperonin homolog on immunoblotting. These results suggested that the functional chaperonin homolog in the cytosol may be transported into the mitochondria and the protein may be processed to mitochondrial HSP60 in the organella.

Progesterone treatment decreases sulfate carbohydrate antigen on endometrial carcinoma cells and inhibits the cell binding to laminin

To investigate the effects of progesterone on endometrial carcinoma, sulfated carbohydrate antigen was studied using a monoclonal antibody, termed E8, that reacts with sulfatide. The reactivity of monoclonal antibody (MAb) E8 with endometrial carcinoma tissues decreased when patients were treated with medroxyprogesterone acetate (MPA). A reduction of reactivity of MAb E8 with endometrial carcinoma cells was also observed in in vitro examinations using an endometrial carcinoma cell line, Ishikawa cells incubated in MPA-containing medium. Sulfated carbohydrate, such as sulfatide, is the site of binding with laminin. The binding of cell surface components with laminin is thought to be an initial step in the invasion and metastasis of carcinoma cells. The MPA-treated Ishikawa cells bound to laminin-coated dishes less [corrected] efficiently than nontreated cells. MPA treatment of endometrial carcinoma reduces the sulfatide carbohydrate on the carcinoma cell surface and may be clinically more effective in reducing cell binding to laminin.

Detection of beta cell-specific DNA damage in streptozotocin-treated rats by in situ nick translation with immunostaining of alpha cells

In situ nick translation with immunostaining of alpha cells could demonstrate the specific localization of streptozotocin- (STZ) induced DNA damage in beta cells using in vivo materials. The extent of DNA damage was determined through autoradiography by counting the number of grains in the nucleus of the alpha, beta, and exocrine cells of the rat pancreas. Subsequently, in situ nick translation with immunostaining of alpha cells was carried out in a pancreas pretreated with STZ. The number of grains observed in the beta cells of the STZ-treated groups was significantly higher than that in the control group. DNA damage of pancreatic beta cells due to STZ could be detected visually using in situ nick translation with immunostaining of alpha cells. Moreover, it was also possible to compare the DNA damage in the individual cells of the pancreas.

Effect of motilin on colonic motor activity in the interdigestive state in conscious dogs

The aim of the present study was to investigate the effect of motilin at various doses on colonic motility in the interdigestive state. Colonic motility was investigated in five dogs equipped with strain gauge force transducers on the gastric antrum, and on the proximal, middle, and distal colon. Exogenously infused motilin (0.2, 0.5, 1.0 and 2.0 micrograms/kg-hr) dose-dependently increased colonic motility, but the doses of motilin that significantly enhanced colonic motility were 1.0 and 2.0 micrograms/kg-hr in all areas of the colon. Motilin at 0.2 microgram/kg-hr increased the plasma motilin concentration to almost equal to the physiological peak values. The excitatory effect of motilin (2.0 microgram/kg-hr) was abolished by atropine but was not affected by hexamethonium. These results indicate that exogenously infused motilin, which increased plasma motilin concentration to above the physiological peak level, stimulated colonic motility by affecting postsynaptic cholinergic neurons.

Early postoperative evaluation of pylorus-preserving gastrectomy for gastric cancer

Early postoperative evaluation was prospectively performed in 35 gastric cancer patients after pylorus-preserving gastrectomy (PPG) between 1989 and 1991, comparing the results with those of 29 patients who underwent conventional distal gastrectomy (CDG). Surgical stress, including the duration of operation (149.0 +/- 4.3 minutes) and the total volume of bleeding at operation (97.0 +/- 11.2 g), was significantly less in the PPG patients. Early postoperative complications were seen in 31% after PPG and in 35% after CDG. The most frequent complication in PPG patients was remnant gastric stasis (23%). Endoscopy showed redness or erosion (or both) of the gastric remnant in 17% after PPG and in 81% after CDG. Bile regurgitation was demonstrated in 11% after PPG and in 62% after CDG. In PPG patients, the pyloric ring opened and closed during the examination. Gastric pH was 4.2 +/- 0.4 in PPG patients but was significantly lower in CDG patients. The resting gallbladder area, examined by ultrasonography, demonstrated no changes after PPG but was significantly enlarged after CDG (from 11.3 +/- 1.2 cm2 to 15.8 +/- 1.5 cm2 at 2 weeks). The percentage of the original resting gallbladder area at 20 minutes after injection of cerulein increased slightly in PPG patients but recovered thereafter, whereas in CDG patients it increased significantly (from 39.4 +/- 8.3% to 66.7 +/- 9.1% at 2 weeks). No gallstone formation was detected throughout the observation period after PPG, whereas after CDG it was detected in two patients at 1 year.(ABSTRACT TRUNCATED AT 250 WORDS)

[Gastric emptying of semi-solid meal in normal man with special reference to relationship between plasma acetoaminophen concentrations and gastric emptying time]

Correlation between gastric emptying time measured by a radioisotope method and plasma acetoaminophen level was studied in 11 preoperative early gastric cancer in semisolid meal. A significant correlation was found between both gastric emptying half-time and plasma acetoaminophen level at 30, 45 minutes after ingestion of meal, and plasma acetoaminophen level at maximum. We conclude that acetoaminophen analysis is useful to measure gastric emptying at semisolid meal.

Isolation of 115 human chromosome 8-specific expressed-sequence tags by exon amplification

Exon-amplification experiments were undertaken to isolate potentially transcribable sequences from cosmid clones that previously had been mapped to subchromosomal bands of human chromosome 8 by fluorescence in situ hybridization. From 253 cosmids subjected to this procedure so far, we isolated 169 fragments and confirmed that they had been derived from the original cosmid clones. Among them, 38 revealed homology to repetitive DNA sequences such as Alu and L1 elements. The other 131 were unique sequences, but of these only 115 contained discernible open reading frames. Among these 115 sequences, 15 were identical to parts of six known genes listed in the public database. On the basis of information derived from mapping the original cosmid clones, we were able to localize two of these known genes, zinc finger protein 7 and heat shock transcription factor 1, to 8q24.3. Furthermore, we have proven that some of these clones are parts of the transcribed products by an exon connection method or by isolation of a novel cDNA that is homologous to murine clathrin-associated protein. The expressed-sequence tags isolated here will be useful resources for a transcriptional map of chromosome 8 and for isolation of new genes.

Isolation of a candidate tumor suppressor gene on chromosome 8p21.3-p22 that is homologous to an extracellular domain of the PDGF receptor beta gene

We have isolated a candidate tumor suppressor gene from a 600-kb region on chromosome 8p21.3-p22 that is commonly deleted in sporadic hepatocellular carcinomas (HCC), colorectal cancers (CRC), and non-small cell lung cancers (NSCLC). As this gene encodes a protein of 375 amino acids that bears significant sequence similarity to the extracellular (ligand-binding domain of platelet-derived growth factor receptor beta, we have designated it PRLTS (PDGF-receptor beta-like tumor suppressor). Structural rearrangement involving this gene was found in a sporadic NSCLC. In addition, somatic missense and frame-shift mutations were found in two HCCs and one CRC. These findings indicate that inactivation of the PRLTS gene may play a significant role in development of some carcinomas.

Potentiation of the cytotoxicity of chloroethylnitrosourea by O6-arylmethylguanines

It was reported recently that monomeric O6-benzylguanine (1) acts as an alternative substrate for a DNA repair enzyme, O6-alkylguanine-DNA alkyltransferase (AGT), and that therefore pretreatment of cells with 1 induces depletion of AGT resulting in an enhanced cytotoxic response to alkylating antitumor agents. In order to study the interaction of O6-benzylguanine derivatives with AGT and to obtain greater AGT depletion, we synthesized the following O6-arylmethylguanine derivatives and related compounds: O6-(4-, 3- and 2-fluorobenzyl)guanines (2, 3, 4), O6-(4-, 3- and 2-trifluoromethylbenzyl)guanines (5, 6, 7), O6-(4-, 3- and 2-pyridylmethyl)guanines (8, 9, 10), O6-(2- and 1-naphthylmethyl)guanines (11, 12), O6-biphenylmethylguanine (13), S and Se analogues of O6-benzylguanine (14, 15) and O6-phenylguanine (16). Ten of these are new compounds. All these compounds were tested for their potentiation of N'-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-N-(2-chloroethyl)-N-nitrosou rea (ACNU) cytotoxicity using HeLa S3 and C6-1 cells. Compounds 2, 3, 5, 8, 9, 11 and 13 were active, as was 1. Compounds 7 and 12, with a substituent at the alpha position of the benzyl group, and compound 10, the alpha-nitrogen analogue of 1, were almost completely devoid of potentiating activity. These results suggest that the alpha-position of the O6-benzyl group plays an important role in the interaction of O6-benzylguanines with AGT. Of the other compounds, 4 and 6 exhibited very weak activity and 14, 15 and 16 were inactive. Possible reasons for these differences in activity are discussed in relation to the biomimetic dealkylation rates of O6-benzylguanine derivatives and the chemical characteristics of their substituents.

Exogenous insulin dose-dependently suppresses glucopenia-induced glucagon secretion from perfused rat pancreas

To clarify the role of insulin in modulating the glucagon response to glucose concentration changes, we investigated the effects of exogenous insulin (10 mU/mL, 100 mU/mL, and 3.3 U/mL) on responses to high glucose (5.6-->16.7 mmol/L), low glucose (5.6-->1.4 mmol/L), and arginine (10 mmol/L) stimulation using the perfused rat pancreas. Although glucagon levels were slightly suppressed by all of the exogenous insulin concentrations tested for the initial few minutes at 5.6 mmol/L glucose, baseline levels were maintained thereafter. Glucagon responses to high or normal glucose concentrations were not altered, but glucopenia-induced glucagon secretion was significantly suppressed as compared with that of controls (0.77 +/- 0.14 ng/min [10 mU/mL, n = 5], 0.55 +/- 0.14 ng/min [100 mU/mL, n = 5], 0.27 +/- 0.13 ng/min [3.3 U/mL, n = 5] v 1.38 +/- 0.20 ng/min [controls, n = 9], P < 0.05, respectively). The first phase of the glucagon response to arginine was potentiated (2.03 +/- 0.24 v 1.17 +/- 0.22 ng/min, P < .05) by 10 mU/mL exogenous insulin. The second phase of the glucagon response to arginine was significantly suppressed in the presence of higher concentrations of exogenous insulin (1.16 +/- 0.23 ng/min [100 mU/mL], 0.96 +/- 0.08 ng/min [3.3 U/mL] v 1.57 +/- 0.17 ng/min, P < .05, respectively). These results suggest that glucagon secretion is modified by the combined suppressive effects of glucose and insulin, although it is mainly glucose that mediates glucagon secretion in the physiological glucose range. Glucopenia- or arginine-induced glucagon secretion is suppressed by insulin.

[Maternal serum alpha-fetoprotein as a screening test for fetal Down syndrome]

An association between a low maternal serum alpha-fetoprotein (MSAFP) level and an increased incidence of Down syndrome is well documented. This study was undertaken to elucidate the diagnostic efficacy of MSAFP as a screening test for Down syndrome in 711 Japanese women who underwent genetic amniocentesis between 14 and 20 gestational weeks of age in Hyogo Medical College Hospital. The mean value for the multiple of the median (MoM) of the MSAFP level in 11 pregnancies associated with Down syndrome was 0.78 +/- 0.47 and 1.12 +/- 0.67, respectively. A cut-off value of < 0.45, < 0.50, < 0.55 and < 0.60 MoM yielded negative predictive values of 98.6%, 98.5%, 99.0% and 99.2%, positive predictive values of 6.3%, 4.0%, 9.1% and 8.6%, a sensitivity of 9.1%, 9.1%, 36.4% and 54.5%, and false positive rates of 2.1%, 3.4%, 5.7% and 9.1%, respectively. The combining of MSAFP and maternal age improves the expected results of a strategy for Down syndrome.

The role of CD4+ and CD8+ T cells in protective immunity to the murine nematode parasite Trichuris muris

The role of CD4+ and CD8+ T cells in protective immunity to Trichuris muris was studied in CD4+ or CD8+ or both CD4+ and CD8+ T cell-depleted BALB/c mice. To assess in vivo depletion of T-cell subsets, CD4+ and CD8+ T cells in the Peyer's patches, the mesenteric lymph nodes (MLN), and the spleens of mice treated with T cell-specific monoclonal antibodies (MoAbs) were analysed by FACS. CD4+ T cells were selectively depleted in mice injected with anti-CD4 MoAb i.p. and injection of anti-CD8 MoAb resulted in selective depletion of CD8+ T cells. The expulsion of T. muris was inhibited in CD4+ T cell-depleted mice and numerous worms were detected in the large intestine on days 14 and 21 after infection, although no suppression of protective immunity to T. muris was observed in CD8+ T cell-depleted mice. Moreover, there was no difference in suppression of protective immunity to T. muris between CD4+ T cell-depleted and both CD4+ and CD8+ T cells play a central role in protective immunity to T. muris infection.

Cloning of a cDNA coding for porcine zona pellucida glycoprotein ZP1 and its genomic organization

The zona pellucida composed of three or four glycoproteins plays important roles in fertilization. Our previous study showed that porcine ZP1, one of the major glycoproteins of porcine zona pellucida, was divided into two components (porcine ZP4 and ZP2), and suggested it was a homologue of mouse ZP2. In this paper we report the cloning of a cDNA for porcine ZP1 and its genomic organization. The deduced amino acid sequence of porcine ZP1 shared a 54% and 63% identity with those of mouse and human ZP2, respectively. Genomic organization of porcine ZP1 was also similar to that of mouse ZP2. The transcript of porcine ZP1 gene was detected only in growing oocytes.

[Clinical significance of ultrasonographic screening for Down syndrome in the second trimester]

OBJECTIVE

This study was undertaken to evaluate the clinical significance of ultrasonographic screening for the detection of Down syndrome in the second trimester of pregnancy of Japanese women.

MATERIALS AND METHODS

BPD (biparietal diameter), FL (femur length), BPD/FL ratio and M/E FL (measured/expected femur length) ratio were measured in 734 normal second-trimester fetuses and 13 consecutive Down syndrome fetuses undergoing genetic amniocentesis mainly for advanced maternal age.

RESULTS

Two fetuses with Down syndrome had small BPD, three fetuses had a short femur length, four fetuses had a high BPD/FL ratio and four fetuses had a low M/E FL ratio. A cutoff value of 1.5SD below the mean value for the normal populations for BPD and FL, that of above 1.5SD for BPD/FL ratio, and that of 0.91 or less for M/E FL ratio yielded a sensitivity of 15.4, 23.1, 30.8 and 30.8% and false positive rates of 2.7, 6.0, 5.7 and 11.4%, respectively.

CONCLUSION

The ultrasonographic measurements of femur length for the screening of Down syndrome in the Japanese population revealed the low discriminative ability reported in recent studies conducted in Western countries. Further investigation would be necessary to apply it as the routine screening method for Down syndrome in clinical practice.

Neural cell adhesion molecule and perineural invasion in gallbladder cancer

To clarify the role of neural cell adhesion molecule (NCAM) in perineural invasion, NCAM expression was studied by immunohistochemical staining in 26 cases with gallbladder cancer. In gallbladder cancer, the incidence of perineural invasion and that of positive NCAM expression was 42% and 31%, respectively, which are less frequent than those of bile duct cancer in our previous report. Perineural invasion was observed in 88% of the patients with positive expression of NCAM and in 22% of those with negative expression. The former is similar to that of bile duct cancer but the latter is significantly lower. Eighty percent of the cancer cells that invaded the perineural space were positive for NCAM, when the primary tumor was positive for NCAM expression. Therefore, in gallbladder cancer, positive cells in NCAM expression likely invade the perineural spaces. However, the perineural invasion of negative cells in NCAM expression is not likely to occur as compared to bile duct cancer. In conclusion, perineural invasion in gallbladder cancer is not as common as in bile duct cancer, but the role of NCAM in perineural invasion is more important in gallbladder cancer than in bile duct cancer.

Germline mutations of the RET proto-oncogene in eight Japanese patients with multiple endocrine neoplasia type 2A (MEN2A)

Multiple endocrine neoplasia type 2A (MEN2A) is a dominantly inherited cancer syndrome characterized by medullary thyroid carcinoma, pheochromocytoma, and parathyroid hyperplasia. The gene responsible for MEN2A was localized by linkage analysis to chromosome 10q11.2 in 1987, and recently mutations in RET, a proto-oncogene in the candidate region, were discovered in patients with MEN. The majority of mutations found so far in MEN2A patients have been located in nucleotide sequences encoding cysteine residues in the extracellular domain of RET. To characterize MEN2A germline alterations in the Japanese population, we screened DNA from eight unrelated patients for mutations in exons 10 and 11 of the RET proto-oncogene and found mutations in all eight patients, at codons 618, 620, or 634; each of these sites encodes a cysteine residue in the extracellular domain of RET. The mutations were confirmed in other affected individuals in the respective families by digestion of polymerase chain reaction (PCR) products containing the mutated codons with restriction enzymes (Rs alpha I, CfoI, or AluI) for which cleavage sites had been generated by the specific genetic alteration. These PCR-restriction enzyme systems will be useful for genetic diagnosis in members of families carrying these mutations.

Effect of dibutyryl cyclic AMP on the cell cycle of human pancreatic cancer inoculated in nude mice

The prognosis of pancreatic cancer is very poor because of its high malignant potential. To improve the prognosis of pancreatic cancer, a decrease in the grade of malignancy by dibutyryl cyclic AMP (db-cAMP), a differentiation inducer, was attempted using human pancreatic cancer cell line inoculated to nude mice. In this study, 0.1 or 5.0 mumol/animal/day of db-cAMP was administered for 7 consecutive days in short-term group animals and for 28 consecutive days in long-term group animals. Animals in both groups are sacrificed 28 days after first administration of db-cAMP, and tumor size, histology, and cell cycle analysis using flow cytometry (FCM) were studied. Tumor size and histology showed no significant changes by db-cAMP. However, in cell cycle analysis, 5.0 mumol/animal/day of db-cAMP brought significant block of the cell cycle phases between G1 and S in the short-term group and the phase between S and G2/M in the long-term group, indicating a decrease in cell cycle speed and, consequently, a decrease in the proliferation of tumor cell. The results show that db-cAMP may be useful in decreasing the grade of malignancy of pancreatic cancer.